The first steps of theory finding took place in 1970, when Landrum Shettles and David Rorvik, two of the most famous obstetricians and gynecologists in USA, published their famous book “How to choose the sex of your baby?”
They explained that the male (Y) sperm is smaller, lighter and faster than the female sperm (X). They proposed a new theory on how to give birth to boys and girls. The theory is based on the ovulation timing. They recommended that parents desiring a girl are encouraged to have sex three or four days before ovulation. The weaker and smaller male sperm will die within the first two days while the stronger and bigger female sperm will be able to live longer and fertilize the ovum once released from the ovary. On the other hand, it is better for boy-desiring couples to have sex closest to the time when a woman's ovum is released, giving better chance for the male sperm to fertilize the ovum.
Upon starting to put the theory into practice, researchers were divided into two groups. One group supports the theory, claiming 75% success rate as mentioned in the article published by the Independent (UK) in 2002 under the title “Can you choose your baby's sex?” by Roger Dobson and republished on 25 Aug. 2006 by Independent Online. The other group strongly opposes the theory, on the grounds that scientific evidence and data tend to disprove it, as claimed in an article entitled “Gender Selection Methods by Intercourse Timing: Review of Published Scientific Articles” (fertilityfriend.com) 1998-2006.
The above-mentioned article listed the following three researches as refuting Shettles theory:    (John T. France and colleagues, for example, in an article published in 1992 in The International Journal of Fertility say “ . . . our findings tend to disprove the Shettles theory . . . ” Likewise, R H Gray, in a 1991 article in American Journal of Obstetrics and Gynecology says that the Shettles method is contradicted by scientific data. Finally, in a 1995 study published in the New England Journal of Medicine, researchers Allen Wilcox, Clarice Weinberg and Donna Baird say that “the timing of sexual intercourse in relation to ovulation has no bearing on the sex of the baby.”)
However, prior researches suffer some disadvantages. I believe that Shettles theory includes the following mistakes:    1. The theory could not explain the logical but not factual assumption that “if the male sperm always reaches the ovum first, then all the babies must be boys.”    2. Shettles claimed that boy-desiring couples must have intercourse just before ovulation. This is definitely wrong since the bigger and stronger female sperm will then have a better chance to reach the ovum and fertilize it before the male sperm.    3. Shettles did not know that there are factors, of course after Allah's Will, that determine the sex of the baby other than the intercourse timing. I believe that the thickness of the ovum wall is the most important factor representing the major obstacle encountering sperms. Hence, baby love male capsules attenuate the coat of the ovum, so that the male sperm can reach the ovum first.
The theory of the ovum wall thickness explains the most important factor determining the sex of the baby. On the other hand, the theory of cell fragility offers an ideal solution for treating the thickness of the ovum wall. It also offers a solution for some types of infertility and chronic diseases for which modern medicine cannot offer a cure.